The 25-year-old Romanian is the third woman to qualify for the year-ending event after Angelique Kerber and Serena Williams, reports Xinhua.

Both of her previous appearances were in the first two editions of the WTA Finals held in Singapore, highlighted by her win over then world No.1 Serena in the round-robin stage in 2014 en route to the finals followed by last year's showing where she defeated the 2015 US Open champion Flavia Pennetta in the round-robin stage.

Halep is one of four players to win three WTA singles titles in 2016 (also Azarenka, Kerber and Stephens), clinching her second Premier Mandatory trophy at the Madrid Open and back-to-back titles at the Bucharest Open and Rogers Cup in Montreal.

She has brought her win-loss record to 43-14 after reaching the Wuhan Open semi-finals. In addition, Halep reached two semi-finals at the International Sydney and Western & Southern Open in Cincinnati and four quarterfinals at the BNP Paribas Open in Indian Wells, Miami Open, Wimbledon and the US Open.

"It means a lot to qualify for the WTA Finals Singapore -- it was one of my goals this year," said Halep.

"It will be my third time in a row competing at the WTA Finals and I hope I play great. I have great memories from 2014 and am confident I can do well. I will be very focused."